In the field of the remote subscription management such as MCIM (Machine Communication Identity Module) defined in 3GPP TR 33.812, a registration operator (RO) provides 3GPP connectivity for communication devices to request downloading and provisioning of MCIM credentials from provisioning servers. Each communication device is pre-allocated (pre-installed) a unique subscription identity such as IMSI (International Mobile Subscriber Identity) and a Corresponding credential such as a secret key (hereinafter also referred to as “key” or “K”) and uses the subscription identity and key to attach to the RO. To pre-allocate a unique pair of IMSI/K to each communication device for initial connectivity has the following drawbacks. First, it takes cost that the RO delivers unique pairs of IMSI/K to device manufactures and the device manufactures configure the unique pairs of IMSI/K to their communication devices. Second, some of the pre-allocated IMSI may not be used when the communication device supports radio access technology other than 3GPP network access technology. This leads to waste IMSI numbering space.
A solution to overcome the above drawbacks is to pre-allocate the single same pair of IMSI/K to a plurality of communication devices. However, this solution also has drawbacks. Because the RO cannot handle a plurality of attachment requests with the same IMSI at the same time, it is required to carefully manage when and which communication devices can use the common IMSI to attach to the RO for the MCIM provisioning. This is, however, obviously cumbersome and costly because careful scheduling is needed and careful modification of the schedule needs to be performed when another communication device is added with the common IMSI.